It's the not the tread but rather the compound. Look at their site. Inov8 has three compounds, an E for endurace, and S for sticky and a tricompound that tries to maximize both. No word on the tri-compound yet but the E is definitely not as sticky as the S.

Also it depends on your surface. I love my roclite 315 (Endurance compound) but the tread is a bit too aggressive for slick rock or hard pack trail until it wears down. It's a bit like walking on stilts and the deep treads minimize rubber contact on rock, which is the exact opposite that you want on slickrock.

So if your surface is a consolidated rock, like slickrock or granite slabs, and wet I'd actually look at one of their lower profile outsoles. The trail-roc, terrafly, or even a road shoe like the f-lite with sticky rubber would be best. If you have more talus or river rock gravel then the more aggressive tread like a roclite or x-talon is useful.

I wear the roclite 295 (sticky sole) on the majority of my trips and I'm quite happy with the stickiness and versatility. There's enough tread depth to work in mud/snow, while the sticky compound is great on slick rocks during river crossings. But I agree with the above posts, if you are doing primarily slick rock, get something with less tread depth like the flite or trailroc.

I don't know what fjells are (is that same as the british "Fell"?) but if it's the same as british mountains then you'll deal with more loose rock, scree, gravel, grass, and mud. In that case you'd want more "traction" which is exactly what the x-talon and roclites were designed for. Traction is the ability of a shoe to "dig" into soft or loose ground and not slip. Friction is the ability to "stick" onto hard and smooth surfaces (like tarmac, concrete, granite slabs). So decide what's best for your local geography.

For comparison, I live in the American southwest. We have a lot of sand, gravel, scree, and hardpacked trails. So I went with the roclite since it has an aggressive tread but wasn't too much like cleats (like the x-talon or bare-grips tread patterns). I got the 315s which have endurance rubber since the desert is brutal and abrasive on anything not made of stone. This gave me the most security on desert cross-country trips and wetter forested hikes. Now that I hike in canyons and do more climbing I'm looking at the trail-rocs (didn't exist when I bought my shoes originally) since they're a little flatter and my roclites don't feel too secure on polished slickrock with the non stick rubber..

For city life I use flites with sticky rubber and they've held up well on very slick cement in the rain. I've been impressed with the wear too so I'm not going to worry/bother with endurance rubber on future purchases.

So that's my rationale for generally dry and rocky hiking in the American West. Hopefully it'll help you pick a tread pattern.

Personally I'd get a roclite if I was spending more time on looser ground or a trailroc for harder surfaces, but either is a good all around choice to start with. Then you can decide later on if you want flatter or more aggressive tread for your preferred hiking conditions.

You might also want to consider some of La Sportiva's offerings if you're not married to Inov-8. They offer some of the grippiest rubber compounds available in lightweight trail runners. My only experience with the brand has been a pair of Vertical K's I bought to try out that are too short for me. I haven't been able to use them due to sizing but they feel comfortable. So this isn't a recommendation per se, but a suggestion of an alternate brand to check out for sticky climbing shoe rubber used in running shoes.

Inov-8 have changed some of their models for 2013. I can no longer wear the Roclite 295 as the new model is a much narrower fit, even after upsizing, than the previous version. So if you're ordering over the web rather than trying on in a store, the Shoefitr app sizing guidelines may be out of date.

Personally I cannot wear the F-lite or X-talon models (Performance last) as they are far too narrow for me. The old model Roclite 295s (Comfort) were good, but the Trailroc 245s (Anatomic last) feel like a custom fit for me – absolutely perfect. Note that last and compound are different classifications. The former refers to shape, the latter grip and wear-rating.

Nathan: Okay, thanks for pointing La Sportiva out, i'll check them out – i've only heard good things about them, but never owned any shoe from them.

– Anybody knows if they're a "narrow" brand?

Stuart: Thanks! My plan is to buy them from an online shop, as there aren't any shop near me that has a big selection of Inov8. I'll make sure to make correspondence with Inov8 or the dealer before purchase about sizing, and i'll probably order a couple of sizes of 2-3 different pairs at the same time and send the rest back. Having narrow feet has made me buy way too many technical shoes over the years, that i ended up regretting. So i'm prepared this time to do a thorough research!

Peter, I found that runningwarehouse.com has great advice on sizing shoes. For each shoe they have a "how it fits" section that is pretty good at letting you know whether the shoe runs a bit long, narrow, short, fat, whatever. I used this to help me narrow down the sizing for my 195s (which apparently run a half size bigger than a "normal" shoe). Since I already had 315s that I liked, I was able to do a pretty decent virtual comparison that worked out well for me with my next online purchase.

So if you have a shoe size that normally works for you in trail runners (or you own an existing pair of shoes offered by runningwarehouse) you can get a fairly decent idea of what will work.

Peter – I see that shoefitr now lists both old and new versions of the Roclite 295. That is recent, as the last time I looked they only had the old model. I've not been able to do a direct comparison between old and new Roclite 295s as the software thinks they are the same. However doing a three-way comparison with the TrailRoc 245, shoefitr now suggests going 1/2 size larger in the new model than the old. That wasn't enough for me widthwise, and 1 size larger felt too long. For reference I wear 10.5 (all sizes US) in the old Roclite 295, 11 in the Roclite 312GTX and 11 in the Trailroc 245. shoefitr suggested I should wear the new Roclite 295 in 11.5 and strangely the old Roclite 295 in 11 based on my Trailroc 245 sizing.

In contrast, Zappos replaced the picture of the Roclite 295 to show the new model, but retained all the reviews and fit feedback for the old model.

The Roclite 285 has been replaced by the Roclite 243 (which I see they now say has a 'Precision' fit – so confusing). The 285 has the Performance last, which is narrower than the 295 (either model). I believe the Roclite 286GTX also has the Performance last. I'm told the Terrafly line has been updated, although the 303 looks the same as last year. I can't comment on the Terrocs as I've never found any locally.

The Trailroc line was introduced last year, along with the Anatomic last. I wanted to get a pair of 255s (6mm drop) but couldn't find them in stock so settled on the 245s (3mm drop). After wearing the 245s for 3-4 months I tried a pair of 255s through Zappos and sent them back. Between the amount of cushioning around the heel, and the plastic met-cradle on the outside, the heel felt much narrower and was decidedly uncomfortable. I recently acquired a second pair of 245s and they fit as the first pair did. Initially I was concerned about the 3mm drop, but my left knee and ankle are much happier than they were in any other shoes I've worn. These are my go-to shoes outside of winter and mud season.

Take a look at the combined footbed and drop measurements for each shoe to get an idea of how much cushion exists. I started with a 6mm footbed with 6mm drop, then moved to 6mm footbed with 3mm drop. The latter's sole is much more flexible but the Trailroc 245 has some form of plate in the sole and that helps protect against sharp rocks. There's less roll in my ankle on the lower drop shoes, but that also may be a function of the smaller lugs on the Trailrocs than on the Roclites.

On one of my regular trail running routes I wade a swift creek that is flowing on bedrock, so it is very slick. The stickiest are the terrafly's, followed by the roclite 315's, and the flyroc's are the worst. Haven't waded with the 400's as they are a goretex boot.

I've found the LaSportiva's to be very narrow and much narrower than the RocLite's. Saying that, I found both to be comfortable and am a Innov-8 wearer now. Hard to believe how light the 315's are while giving me great support.

for about a decade. This is a harder, more durable version of c4 rockclimbing soles with a "tread" added. At first I did this to make shoes that were grippy for canyoneering and walking on slippery rock in water, as per the intended application of this soling material. Because the "dot tread" I was skeptical of their actual application to regular hiking since I assumed a more conventional style of tread was important since all running/hiking shoes I have ever seen fit that pattern, more or less. Possibly the conventional tread style is an accommodation for lack of grip of the material itself, as a nod to more durability. I was surprised by this, but is was a great demo of what a previous poster mentioned – in most case grip come from predominantly the material, not the tread.

Anyway, I inevitably used the aquastealth soles outside of the slimy rocks in the river, and I discovered the grip on all kinds of surfaces was excellent with zero detrimental effects (for me) of the "weird" tread pattern on gravel down to sand against rock. On the other side, any surface where you can get a square cm of contact against a fixed surface there was a very marked improvement in the grip. This was a genuine surprise for me.

I found that, leaving aside the durability issue, that this is basically the best material I have ever used for hiking in any condition I can think of. OK, I don't do snow that often, and this is just my personal observations for myself. Also I discovered that there is a kind of wax used at my local grocery store, that when very fresh, you can virtually skate on with these souls, but I am able to avoid/enjoy that rare circumstance now. But I basically never *slip* on anything now except perhaps the occasional roll on an isolated marble-sized or larger rock I didn't see because I wasn't paying attention. For me the same thing would have happen in this situation regardless of sole, and I come to a stop faster. My amateur analysis is that this is because of what I mentioned above, that the total area required to get a good slide-proof grip is so small.

So if you found a pair of shoes you really love, except for the grip, you could try resoling them with this stuff. I have found that the durability is not as bad as I thought it would be. You STILL may wear out light hiking shoes before the souls wear out.

Pros: probably the best grip possible without using rock-climbing soles, seems (to me at least) to work on all kinds of surfaces, can apply to any shoe you really like, great in water as well.

Cons: price, durability hit, actually have to mod the shoes, or have them modded for you. Marking, especially for the first few weeks. Keep them off your kitchen linoleum. Also you will be much easier to track by the law, since you will have a pretty unique footprint.

Yeah, they are kind of web amateurs over there at 5-10. If you hit the "buy" button (US purchase)I think it comes up. It is pretty expensive like $34.95 for size reg. They used to sell me large sheets of it before they had actual kits. In my experience the kits are pretty over-sized and the smaller ones are in fact cheaper, so if you check the exact size you may be able to order the cheapest one that will work.

You do get a large tube of barge cement with the kit thought. WOO HOO!